Basic Terminology of Structural Vibration The term vibration describes repetitive motion that can be measured and observed in a structure. Unwanted vibration can cause fatigue or degrade the performance of the structure. Therefore it is desirable to eliminate or reduce the effects of vibration. In other cases, vibration is unavoidable or even desirable. In this case, the goal may be to understa...

The technique of tracing along magnetic field lines is widely used in magnetospheric physics to provide a ‘‘magnetic frame of reference’’ that facilitates both the planning of experiments and the interpretation of observations. The precision of any such magnetic frame of reference depends critically on the accurate representation of the various sources of magnetic field in the magnetosphere. In...

Under a common potential, a finite mixture of ellipsoidal velocity distributions satisfying the Boltzmann collisionless equation provides a set of integrability conditions that may constrain the population kinematics. They are referred to as conditions of consistency and were discussed in a previous paper on mixtures of axisymmetric populations. As a corollary, these conditions are now extended...

Probabilistic latent component analysis (PLCA) is applied to the problem of gearbox vibration source separation. A model for the probability distribution of gearbox vibration employs a latent variable intended to correspond to a particular vibration source, with the measured vibration at a particular sensor for each source the product of a marginal distribution of vibration by frequency, a marg...

In this study, peak particle velocity (PPV) values for driving three piles with diameters of 40 cm, 50 and 70 cm in a clayey soil through the impact piling method are investigated by an experimental study numerical simulation. An is carried out on scale 1:20 operation. Numerical simulation performed using axisymmetric model PLAXIS 2D finite element software. Properties used obtained from geotec...

Vibration mode-shape comparison between numerical models and experimental data is an essential step in the study of structural finite element model (FEM) updating. The Modal Assurance Criterion (MAC) is the most popular method for such comparison at the moment, which works perfectly well for small and medium sized structures. MAC provides a measure of closeness between the predicted and measure...

For high amplitudes of vibrations, loudspeakers are subject to nonlinear phenomena that are responsible for audible distortions. In order to describe the complex dynamics of the system, the displacement field as well as the radiated sound pressure must be expressed in the time-domain. Thus the present study proposes a transient model of the acoustic radiation of axisymmetric structures. The pre...

Axisymmetric deformations of a uniformly heated pre-buckled and post-buckled thin circular plate reinforced with shape memory alloy (SMA) fibers placed in the radial direction only are studied. Effects of von Kármán’s nonlinearities are incorporated in the problem formulation. The matrix is assumed to be linear thermoelastic and the thermo-mechanical response of the SMA is modeled by one-dimens...